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Message-Id: <1229442720-31056-3-git-send-email-duaneg@dghda.com>
Date: Tue, 16 Dec 2008 15:51:54 +0000
From: "Duane Griffin" <duaneg@...da.com>
To: linux-kernel@...r.kernel.org
Cc: linux-fsdevel@...r.kernel.org, Duane Griffin <duaneg@...da.com>,
Al Viro <viro@...iv.linux.org.uk>,
Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] vfs: ensure page symlinks are NUL-terminated
On-disk data corruption could cause a page link to have its i_size set
to PAGE_SIZE (or a multiple thereof) and its contents all non-NUL.
NUL-terminate the link name to ensure this doesn't cause further
problems for the kernel.
Cc: Al Viro <viro@...iv.linux.org.uk>
Cc: Andrew Morton <akpm@...ux-foundation.org>
Signed-off-by: Duane Griffin <duaneg@...da.com>
---
fs/namei.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/fs/namei.c b/fs/namei.c
index af3783f..2416922 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2750,13 +2750,16 @@ int vfs_follow_link(struct nameidata *nd, const char *link)
/* get the link contents into pagecache */
static char *page_getlink(struct dentry * dentry, struct page **ppage)
{
- struct page * page;
+ char *kaddr;
+ struct page *page;
struct address_space *mapping = dentry->d_inode->i_mapping;
page = read_mapping_page(mapping, 0, NULL);
if (IS_ERR(page))
return (char*)page;
*ppage = page;
- return kmap(page);
+ kaddr = kmap(page);
+ nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1);
+ return kaddr;
}
int page_readlink(struct dentry *dentry, char __user *buffer, int buflen)
--
1.6.0.4
--
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